A current conventional vehicle wheel alignment system uses sensors or heads that are attached to the wheels of a vehicle to measure various angles of the wheels and suspension. These angles are communicated to a host system, where they are used in the calculation of vehicle alignment angles. In the standard conventional aligner configuration, four alignment heads are attached to the wheels of a vehicle. Each sensor head comprises two horizontal or toe measurement sensors and two vertical or camber/ pitch sensors. Each sensor head also contains electronics to support overall sensor data acquisition as well as communications with the aligner console, local user input, and local display for status feedback, diagnostics and calibration support. The four sensors and electronics as well as the mechanical housing that makes up each head necessarily is duplicated four times, as there is one for each wheel.
In recent years, wheels of motor vehicles have been aligned in some shops using a computer-aided, three-dimensional (3D) machine vision alignment system. In such a system, one or more cameras view targets attached to the wheels of the vehicle, and a computer in the alignment system analyzes the images of the targets to determine wheel position and alignment of the vehicle wheels from the wheel position data. The computer typically guides an operator to properly adjust the wheels for precise alignment, based on calculations obtained from processing of the image data. A wheel alignment system or aligner of this image processing type is sometimes called a “3D aligner.” An example of a vehicle wheel aligner using such image processing is the Visualiner 3D or “V3D”, commercially available from John Bean Company, Conway, Ark., a division of Snap-on Incorporated.
Alternatively, a machine vision wheel alignment system may include a pair of passive heads and a pair of active sensing heads. The passive heads are for mounting on a first pair of wheels of a vehicle to be measured, and the active sensing heads are for mounting on a second pair of wheels of the vehicle. Each passive head includes a target, and each active sensing head includes an image sensor for producing image data, including an image of a target of one of the passive heads, when the various heads are mounted on the respective wheels of the vehicle. The system also includes a spatial relationship sensor associated with at least one of the active sensing heads, to enable measurement of the spatial relationship between the active sensing heads when the active sensing heads are mounted on wheels of the vehicle. The system further includes a computer for processing the image data relating to observation of the targets, as well as positional data from the spatial relationship sensor, for computation of at least one measurement of the vehicle.
Since each of the above-described wheel alignment systems includes a computer and at least two remote sensor units (e.g., alignment heads, cameras or sensing heads), it is desirable to provide wireless communications between the computer “base station” and the remote sensor units. Typical wireless network structures utilized in such automotive service systems are based on proprietary wireless technologies. In general, non-indigenous proprietary or sole source technologies can provide specific solutions to technical requirements, be fast-to-market, and provide low cost product functionality without expending valuable internal development resources. Unfortunately, these proprietary technologies also generally become obsolete well before the end of a service system product life cycle. They may also constrain overall product performance and reliability to the specific performance and reliability of a sole source device. Often, the changes required to replace a proprietary technology can be expensive and can lead to reliability and service issues.
In contrast, standard or multi-source solutions are designed for a broad consumer market and often fall short of the specific functionality required for automotive service systems in a garage environment. Following the pressures of a consumer market place, standard technologies can also change quickly as the market changes and therefore may require frequent incremental product design changes. Unless these changes are easily accommodated, a hosting product can suffer reliability and service cost consequences. In addition, many standard technologies are designed to reach across a broad market accommodating many different performance and functional requirements. This technical flexibility typically results in complex setup procedures or configurations that can be inadvertently modified by an unsuspecting or untrained user. Sometimes a user may be somewhat familiar with a standard technology and try to modify or adapt a configuration to include unintended devices or features that can detrimentally affect the performance or render the hosting product non-functional.
There exists a need for an apparatus and methodology for a wireless network structure utilizing standard wireless technology for low cost, while also providing simplified installation to a service system host, ease of service bay network setup, and increased network performance.